"Michelle is the ultimate example of a truly strong African American woman," the singer posted on Beyonce.com. "She is a caring mother, she's a loving wife, while at the same time, she is the First Lady!!!!"

"No matter the pressure, and the stress of being under the microscope -- she's humble, loving, and sincere," Beyonce write. "She builds and nurtures her family, while also looking out for so many millions in so many ways."

Beyonce has been a long-standing supporter of the Obama family. She performed Etta James' "At Last" at President Barack Obamas' 2008 inaugural ball and teamed up with the First Lady last year for her Let's Move campaign.

She ended her letter with a personal note. "Michelle, thank you so much for every single thing that u do for us -- I am proud to have my daughter grow up in a world where she has people like you, to look up to."